Description (Taken directly from the application): The Protein Chemistry Core is designed to optimize the efficiency and cost effectiveness of the Program Project by performing laboratory procedures used in common by the Project Investigators. The major focus of the Core will be the use of gas chromatography-mass spectrometry to determine the levels of glycation products and oxidation products in proteins, cells and tissues used in the various Projects. Specific markers for proteins damaged by glycation, glycoxidation, the myeloperoxidase system of activated phagocytes, and reactive nitrogen species will be quantified using stable isotope dilution, negative-ion chemical ionization gas chromatography-mass spectrometry. By centralizing and standardizing procedures, the Core facility will provide a common set of analytical procedures that should facilitate a unified understanding of the molecular mechanisms involved in the genesis of diabetic vascular disease.